1. Field of the Invention
This invention relates generally to a method and medication for treating sexual dysfunction and more specifically to a treating drug-induced sexual dysfunction.
2. Description of Related Art
Sexual dysfunction is commonly associated with antidepressant drugs (J. R. T. Davidson, Sexual dysfunction and antidepressants, Depression 2:233-240 1994,95; Richard Balon, et al., Sexual Dysfunction during antidepressant treatment, J. Clin. Psychiatry Update Monograph, 1:1 November 1994). Patients' complaints relate to decreased libido, erectile dysfunction, orgasmic and ejaculatory problems. Several treatments have been tried to alleviate patients' complaints of sexual dysfunction, but only limited success has been reported (Bartlik, B., Kaplan, P., Kaplan, H. S., Psychostimulants apparently reverse sexual dysfunction secondary to selective serotonin re-uptake inhibitors, J. Sex Mar Ther., 21(4):264-271, Winter 1995). Several pharmacological formulations have been used in attempts to intervene in the onset of this unwanted side effect. They include administering amantadine, amphetamine, buspirone, cyproheptadine, ginseng, Ritalin.RTM., and yohimbine. These attempts at pharmaceutical intervention have not been satisfactory.
The antidepressant, fluoxetine, commercially available under the trade designation Prozac.RTM., has been found to reduce sexual reaction so effectively that it is successfully used to treat premature ejaculation (U.S. Pat. No. 5,151,448). However, for patients seeking only the antidepressant effect of fluoxetine, the associated reduction in libido, reduced or delayed orgasm, delayed ejaculation, and erectile dysfunction is significant enough to prevent patients' use of the drug. It would be highly desirable if antidepressant drugs could be administered without the unwanted side affect of sexual dysfunction.
Estimates of the incidence of sexual dysfunction attributed to antidepressant use vary from approximately 2% to over 90%. The antidepressants commonly reported as most likely to cause sexual dysfunction include heterocyclic antidepressants, monamine oxidase inhibitors, selective serotonin reuptake inhibitors, venlafaxine, bupropion, and nefazodone.
Ginkgo Biloba L. (hereinafter referred to as "Ginkgo") has in the past been used to treat asthma and bronchitis. The Chinese have used it for these purposes for centuries and more recently the German pharmaceutical company, Schwabe, has marketed Gingko as a prescription drug for the same purpose. Gingko is a Japanese name used by German surgeon, Kaempfer in 1712. The plant was known as Salisburia adiantifolia Sm. until Linnaeus, a Swedish botanist, gave it the Latin name, Ginkgo biloba L in 1771. The Ginkgo fruit is known by the Chinese as Pak-Ko.
Christopher Hobbs, in a book titled Ginkgo, Elixir of Youth (Botanica Press, Box 742, Capitola, Calif. 95010, 1991), provides one of the most complete lists of medical uses for Gingko preparations. He presents over 140 references on medical uses of Gingko preparations. His thorough discussion includes traditional Chinese medical uses and modern western medical uses of Gingko preparations. He discusses use of Gingko preparations to treat allergies, loss of alertness, asthma, vertigo, circulatory problems including cerebral insufficiency, low glucose metabolism in the brain, depression, hearing loss, ringing in the ears, heart disease, mental confusion, intellectual weakness, stroke, retina damage, and memory loss. While most traditional Chinese preparations focused on use of the Ginkgo nut, or fruit, most modern preparations are made from the Ginkgo leaves.
A 1992 medical review (Jos Kleijnen and Paul Knipschild, Lancet, v.340, Nov. 7, 1992 cited the main indications for ginkgo as peripheral vascular disease such as intermittent claudication and cerebral insufficiency, where the latter comprised mental confusion, anxiety, dizziness, headache, and other symptoms associated with impaired cerebral circulation. In another study, Ginkgo biloba was found to act as a smooth muscle relaxant. Puglisi et al. (Pharm Res Comm, 20(7): 573, 1988) studied the therapeutic potential of flavonoids from Ginkgo biloba L. in the treatment of respiratory distress found the flavonoids acted on tracheal smooth muscle cells. There has been no evidence that Ginkgo Biloba L. has utility other than for respiratory or vasoregulatory and circulatory complaints.
The Merck Index, 11th ed., Susan Budacari, Ed., (Merck & Co., Rahway N.J., 1989), pg. 693, lists Ginkgo Biloba extract as a defined extract obtained from the leaves of Ginkgo biloba L., also known as Salisburia adiantifolia Smith. Several cites for its preparation are given. Its therapeutic category is "In cerebral and peripheral circulatory disturbances".
All antidepressants are associated with some likelihood of inducing sexual dysfunction. The consequences of sexual dysfunction induced by antidepressants is significant and can result in patients not complying with treatment, leading in turn to relapse in depression and subsequent morbidity and mortality. It clearly would be highly desirable and beneficial to users of antidepressant medication if there were a medication that would alleviate this adverse side-effect of antidepressant medication.